APA (7th ed.) Zitazioa

Hartwig, G. (1881). The polar world: A popular description of man and nature in the Arctic and Antarctic regions of the globe (Segunda edición.). Longmans, Green, and Co.

Chicago Style (17th ed.) Zitazioa

Hartwig, G. The Polar World: A Popular Description of Man and Nature in the Arctic and Antarctic Regions of the Globe. Segunda edición. London, England, United Kingdom: Longmans, Green, and Co, 1881.

MLA (9th ed.) Zitazioa

Hartwig, G. The Polar World: A Popular Description of Man and Nature in the Arctic and Antarctic Regions of the Globe. Segunda edición. Longmans, Green, and Co, 1881.